<!DOCTYPE html>
<html>

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <div id="root"></div>
</body>
<script>
    function App(){
        return (
            `
            <div className="App">
                <h1>Hello Hello</h1>
            </div>
            `
        )
    }
    let html = App();
    console.log(html);
    
    const ReactDom = {
        render:function(App,el){
            el.innerHTML = App;
        }
    }
    ReactDom.render(App(),document.getElementById("root"));
</script>
</html>